1. Field of the Invention
The present invention generally relates to an air filter assembly and more specifically the use and combination of a relatively inexpensive and easily replaced paper filter associated with a conventional polyfoam or fiberglass filter conventionally employed in an intake or an air duct system associated with an air conditioning system or air heating system utilized in homes, offices and the like. Specifically, the air filter assembly includes a rolled filter paper that is drawn across the upstream side of a polyfoam filter or fiberglass filter which acts as a support for the filter paper with the paper filter being replaced periodically by pulling the free end thereof to move a new segment of paper filter from the paper supply roll to a position in alignment and in engagement with the existing filter structure and disposing of the used portion of the paper filter. An inspection window is provided in the air intake louver door normally provided in air conditioning/heating systems to enable the condition of the paper filter to be observed to determine if the paper filter should be changed.
2. Description of the Prior Art
Various efforts have been made to remove various contaminants from air being circulated through an air conditioning or heating system by the provision of a replaceable filter. Such prior devices include the use of a fiberglass or polyfoam filter positioned in the intake opening in the return air duct with the filter being positioned interiorly of a louvered door, grill or the like which can be opened or removed to replace the filter. It is a time consuming job to replace the filter and the filters are relatively expensive especially when considering the frequency of replacing existing conventional filters depending upon the particulate contaminants in the air being circulated. In addition to being time consuming, when the air intake is in a relatively inaccessible position, such as in the ceiling, it is necessary to obtain a ladder to gain access to the intake door or grill in order to replace the filter which becomes a messy and somewhat dangerous operation.
Additionally, efforts have been made to provide a replaceable filter by using a filter media that can be moved transversely across an air flow path. The following U.S. patents exemplify the type of developments in this field of endeavor.
U.S. Pat. No. 3,337,898 PA1 U.S. Pat. No. 4,174,205 PA1 U.S. Pat. No. 4,321,064 PA1 U.S. Pat. No. 4,627,863 PA1 U.S. Pat. No. 4,894,071
While the above patents disclose the general concept of moving a paper filter across an air flow path, the prior art does not disclose the specific combination of components of the present invention which enables the paper filter to be effectively combined with a polyfoam or fiberglass filter and the structure for associating the filter with existing components with the air intake door and opening in a return air duct in an air conditioning or heating system.